F₂ Genetic Analysis And Main Effect Clustering Of F₂ Generation Of Upland Cotton Hybrids In Southern Xinjiang

Cotton is the most widely planted renewable natural textile source in the world and the second-largest crop in China after grain.Cotton is an important textile industry’s main raw material,are the broad masses of life necessities.In recent years,with the improvement of people’s living standards and the development of the textile industry,cotton needs high yield and good fiber quality to meet the needs of high comfort and is more suitable for industrialization.Xinjiang is the largest province in China’s cotton output,accounting for 87.3%of China’s cotton output.4 yield traits and 5fibre quality traits of their 217 varieties（lines）and their 705 F₂crosses of upland cotton were analyzed for their additive and dominance effects by a genetic model with additive,dominance,and their interaction effect with the environment in two years of Alar,south Xinjiang.Based on the additive and dominance effects,all varieties were clustered using cluster analysis of the R software package to explore the potential of the breeding and utilization value of various varieties.It is of great significance to utilize the genetic potential of these parental yield and fiber quality traits in upland cotton breeding in southern Xinjiang.The main results are as follows:1.The additive effect of boll number per plant,lint yield per plant and elongation was significant or extremely significant,but the dominant effect was not significant,indicating that they were controlled by the additive effect.The ratio of the residual variance of each character to phenotype variance was extremely significant,indicating that yield and fiber quality traits were susceptible to environmental effects.The narrow heritability of interaction between the nine traits was close to or equal to 0,indicating that the additive effects of these traits were not significantly different among different places in Alar.2.The results indicated that under the high-density planting mode of"low plant growth（plant height:0.8-1.0m）,high density（225,000-300,000/ha）,early ripe and film cover"in southern Xinjiang province,the additive effects of 217 parents were divided into six categories.The average additive effects of yield and fiber quality traits of 38 varieties（lines）in the sixth group were at a good level.It was easy to obtain offspring with both yield and fiber quality traits through crossing between these varieties（lines）.The second type of varieties（lines）had a better average additive effect on fiber quality traits,while the sixth type of varieties（lines）had a higher average additive effect on yield traits.The progeny with complementary yield and fiber quality traits could be obtained by crossing these two kinds of varieties.The dominance effects of 217 parents were divided into eight categories.The fourth group included 28 varieties（lines）that yield traits and fiber quality traits（except Lint percentage）were all at a better average level in dominance effect,which could be used as parent for hybrid utilization of both yield traits and fiber quality traits.The average value of dominance effect of yield traits was higher in the eighth group,and the average value of dominance effect of fiber quality traits in the fifth group was high.